The subject matter disclosed herein relates to the art of turbomachines and, more particularly, to a seal assembly that inhibits fluid flow in a turbomachine.
In a typical gas turbomachine, combustors receive a supply of pressurized air from a compressor section and a supply of fuel. The pressurized air and fuel are mixed to form a combustible air/fuel mixture. The air/fuel mixture is then ignited and combusted to form hot gases that are directed into a turbine section. Thermal energy from the hot gases is converted to mechanical, rotational energy in the turbine section.
The hot gases are passed from the combustor into the turbine section through a transition duct or piece. Generally, an air duct that delivers cooling air from the compressor surrounds the transition piece. Unless internal surfaces are properly sealed, the hot gases may bypass the turbine section and enter into the air duct. This bypass or leakage flow does not produce any work and thus represent internal loses in the turbomachine. The leakage flow generally passes between adjacent surfaces moving or rotating at variable speeds. Over time, clearances between the variable speed surfaces may increase due to internal rubbing, solid particle erosion, foreign object damage (FOD), and the like. Presently, many turbomachines employ labyrinth seals between the variable speed surfaces to limit the leakage flow. The labyrinth seals create multiple barriers that substantially limit the hot gases from entering into the cooling air flow in the air duct.